Some 4 weeks ago i have brewed what was supposed to be an 11 gal batch of my house American wheat with US-05. Well I had some spills and boil-overs and I landed up with 9 gal of wort with SG 1.050.
So I decided to try a Beano experiment. I split up the batch into 5 gal of SG 1.050 in one fermenter and 4 gal + 1 gal water (SG 1.044) in the other fermenter. I also added three pills of crashed Beano into the second fermenter.
After 3 weeks I took the FG reading and checked the alcohol level and calories of those 2 beers using this site: ProBrewer.com: Beer Specifications Calculator
Here are the results:

As far as the taste goes, the Beano beer is dryer, but not much different then the "normal" beer. The beer without Beano tastes better, but the one with Beano is still drinkable.
Honestly, I think that I won't try using Beano in fermentation anymore. The only way I can see how it may work is if you like a "lite" type cream ales or something similar.

I guess you're right. But on the other hand, I didn't want to end up with an undrinkable beer. I just wanted to see if I could make a decent beer with lower SG, how low will the fermentation go, how much alcohol, is it going to be a "low-cal", what about the taste, etc.
What really surprised me was that after all there wasn't that much difference in FG. I was expecting more difference with Beano.

I've used Beano in the mash on a Belgian Golden Strong Ale. Jamil Z. says to add it in the mash (90 min at 148F), NOT the fermentor. That beer went from like 1.070 down to 1.006.

I think that if the "regular" beer went down to 1.004, then the Beano version would be very similar. Beano will help you chomp down sugars if you get stuck at 1.020, but it can't get your beer lower than 1.000.

Ive used beno in the primary and it give a higher abv and a lower body. Realy if your useing malted grain i wouldnt use it but i once did a beer with 70% unmalted wheat and corn starch and the beno in the primary made it a very nice light beer. Any way that just my 2 bits.